1. Field of the Invention
The present invention relates to friction coupling mechanisms such as brakes wherein a rotatable element is frictionally coupled to a relatively nonrotatable element, and clutches wherein two relatively rotatable elements are coupled and uncoupled. More particularly, the invention relates to friction coupling mechanisms having piston and cylinder assemblies with one piston, which can be used interchangeably in dual disc, single disc and caliper coupling arrangements.
2. Description of the Prior Art
Fluid actuated brakes and clutches having friction members driven outwardly in opposite directions to engage opposed discs have been described in Suppes et al, U.S. Pat. Nos. 3,237,738 and 3,311,205 and 3,584,717, as well as in Montalvo U.S. Pat. Nos. 3,696,900 and 4,175,651. Brakes and clutches disclosed in those patents are compact and easy to service. The concept that when hydraulic force is directly applied to one of two opposed friction shoes or pads, there is a simultaneous application of an equal reaction force indirectly imposed on the other shoe by reason of a self-aligning piston and cylinder assembly has been suggested in G. A. Dotto et al, U.S. Pat. No. 3,081,843 and Montalvo, U.S. Pat. No. 4,175,651.
Despite the wide variety of prior art frictional coupling mechanisms, there continues to be a need for a smaller and more versatile piston and cylinder assembly which is compact, low-priced and suitable for use in smaller brakes and clutches.